Methods of producing an osteoinductive calcium phosphate material for bone grafting

Abstract

The present invention relates to methods for producing biphasic calcium phosphate materials using chemical processing methods including exposure to peroxides. The resulting materials exhibit an osteoinductive needle-like surface morphology and are useful as artificial bone grafts.

What is claimed is: 
     
         1 . A method for inducing bone tissue formation in a patient, the method comprising:
 providing granules for implantation in a patient, the granules comprising hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), wherein the granules have been soaked in a solution comprising an oxidizing agent to produce one or more HA needle or nanorod protrusions from the granules’ surface.   
     
     
         2 . The method of  claim 1  wherein, prior to the soaking step, the granules have been hydrothermally treated. 
     
     
         3 . The method of  claim 2  wherein the hydrothermal treatment comprises autoclaving the granules at about 140° C. 
     
     
         4 . The method of  claim 3  wherein the granule has been autoclaved at about 140° C. for about 8 hours. 
     
     
         5 . The method of  claim 4  wherein the granules have been dried between autoclaving and soaking. 
     
     
         6 . The method of  claim 2  wherein the granules comprise about 60% HA and about 40% β-TCP. 
     
     
         7 . The method of  claim 6  wherein the oxidizing agent is hydrogen peroxide (H 2 O 2 ). 
     
     
         8 . The method of  claim 7  wherein the solution comprises about 50% H 2 O 2 . 
     
     
         9 . The method of  claim 8  wherein the granules have been soaked in a sealed container for about 6 hours. 
     
     
         10 . The method of  claim 2  wherein the hydrothermal treatment comprises autoclaving the granules at a temperature less than 125° C. 
     
     
         11 . The method of  claim 10  wherein the granules comprise about 20% HA and about 80% β-TCP. 
     
     
         12 . The method of  claim 11  wherein the peroxide is hydrogen peroxide (H 2 O 2 ). 
     
     
         13 . The method of  claim 12  wherein the solution comprises about 30% H 2 O 2 . 
     
     
         14 . The method of  claim 13  wherein the granules have been soaked in a sealed container for about 4 hours. 
     
     
         15 . The method of  claim 1  comprising providing the granules for implantation as a bone graft. 
     
     
         16 . The method of  claim 1  comprising providing the granules for implantation to promote wound healing. 
     
     
         17 . The method of  claim 1  comprising providing the granules for implantation in a maxillofacial procedure. 
     
     
         18 . The method of  claim 1  comprising providing the granules in a putty or paste format. 
     
     
         19 . The method of  claim 1  comprising providing the granules as a solid block of material. 
     
     
         20 . The method of  claim 19  comprising trimming the solid block of material to fit a bone defect in the patient.